Testing of Railroad Signal Equipment for Power Line Interference Suceptibility Part I: the Test Jig

A basic need to permit planhing of new ac power lines near railroad-systems is accurate data for the levels of ac interference that upset the operation of railroad signal compenents or systems. Such data would help the power system and railroad system design engineer understand the magnitude of the interference problem, investigate alternative mitigation approaches, and select one that is cost-effective and mutually agreeable. Under EPRI research program RP 1902-1, IITRI developed a body of key railroad signal equipment susceptibility data in cooperation with the major U.S. manufacturers of this equipment. This paper describes the innovative test jig developed under RP 1902-1 which has been applied to obtain susceptibility data for track and line relays, electronic track circuits, and grade-crossing. warning devices. A companion paper (Part II) describes the results of the tests.